When Rosa goes up the stairs to Tommasso's atelier to tell him she can no longer model for him, Ludovico has just left the door open on his way out and she stands in the doorway to look at Tommasso. The cut to inside the atelier shows the door as closed and Rosa has to open it to see him.
When Tommasso proudly displays the pair of tickets to the Metropolitan Opera, they are dated "May 10, 1918". The 1917-18 Met season, however, ended on April 27.